Automatic transmission



Jan. 18, 1949. J. c. CHAMBERLAIN AUTOMATIC TRANSMISSION 3 Sheets-Sheet 1VMT m: mm; Nh\

Filed April 11, 1947 I Inventor Jerry C. Chamberlaih J. C. CHAMBERLAINAUTOMATIC TRANSMISSION Jan. 18, 1949.

3 She'ets-Sheet 2 Filed April 11, 1947 TIIIIIIIIIIIIIIIII'IA InventorJer ry C. Chamberlain B) QM M W W 3 Sheets-Sheet 3 Filed April 11,1947

Inventor Jerry C. Chamberlain Patented Jan. 18, 1949 AUTOMATICTRANSMISSION Jeri-y C. Chamberlain, Phoenix, Aria, assignor ofone-fourth to H. S. Chamberlain and onefourth to Dorothy Chamberlain,

Phoenix, Ariz.

both of Application April 11, 1947, Serial No. 740,949

This invention relates generallyto automatic transmissions, and moreparticularly to a hydraulic gear shift for variable speed gearing,including reverse gearing, of the type used in automotive vehicles.

The primary object of this invention is to provide means wherebysubstantially standard gearing of automotive vehicles will beautomatically shifted to the proper gear ratios for all forward speeds,the device including a three-way valve which may be manually shifted toprovide for forward, reverse and neutral positioning of the gears.

Another object of this invention is to provide means whereby asubstantially constant pressure on the hydraulic fluid of this controlsystem is conveniently obtained.

Another object of this invention is to combine a plurality of clutcheswith the difierent gears, a governor controlled selector valve,by-passing valves and a pressure accumulator in a novel manner.

And a last object to be specifically mentioned is to provide a device ofthis character which is relatively inexpensive and practicable tomanufacture, extremely simple and convenient to install and use, andwhich will give generally eflicient and durable service.

With these objects definitely in view, this invention resides in certainnovel features of construction, combination and arrangement of parts andportions as will be hereinafter described in detail, and particularlyset forth in the appended claims, reference being had to the.accompanying drawings which form a material'part of this Figure 3 is anenlarged vertical sectional view,

of the gears and clutch mechanism, enclosed in a gear box;

Figure 4 is a vertical cross sectional view, taken on the line 4-4 ofFigure 3; r

Figure 5 is a vertical sectional view of the.

selector valve; and

Figure 6 is a horizontal sectionalview of the selector valve, taken onthe line 6-4: in Figure 5.

, Similar characters of reference designate 3 Claims; (01. 74-33c.5)

similar or identical parts and portions throughout the specification andthroughout the several views of the drawings.

Referring now to the drawings in detail, it will be noted that theenvironment wherewith this invention is to be used includes a primemover l0 and a drive shaft, I2, together witha driven shaft l4, on whichis secured the reverse gear wheel IS, the low gear wheel l8, theintermediate gearwheel 20, and the high gear wheel 22. The reverse gearidler gear wheel 24 is shown mounted on a broken shaft 26, and it willbe understood that the above gears and portions of the drive shaft I2and the drivenshaft l4 are mounted in suitable bearings within a gearbox 28, represented in Figure 3. The drive shaft is provided withcorresponding gear wheels 30, 32, 34 and 36 which are in continuousengagement with the reverse and forward speed gears referred to above.

A hydraulic pump 38 is operatively connected by means of a drive shaft40 and co-acting beveled gears 42 associated with the engine drive shaftl2, to pressurize fluid in the conduit 44 which is connected to one sideof the pressure accumulator 46. The construction of this pressureaccumulator will be clearly understood if reference is had to Figure 2,wherein it is shown that the accumulator is. in two halves, eachordinarily of semi-spherical form and provided with annular flanges 48which are secured together by bolts. A flexible diaphragm 50 is securedbetween the flanges 48 to divide the pressure accumulator into twohalves, the space on one side of this diaphragm being filled with thepredetermined quantity of air, and the hydraulic fluid being led intothe other half of the accumulator through the conduit 44. Two outletsv54 and 56, are provided and it should be noted that the outlet 54 isprovided with a one-way valve 58 and that the elasticity of the aircontained in the accumulator functions to maintain a suitable pressureupon the fluid in the other half of the accumulator. I

The outlet 54' is connected to a reservoir 60. The other outlet 56 isconnected to a three-way valve 62, while the lines 64, 66 and 68 connectthe three-way valve to the selector valve 'HL'the reservoir 60, and thecylinder 12, respectively.-

This cylinder-l2 is similar to the othercylim ders 14, 16 and 18 and ineach cylinder is mounted a piston 80, the piston rod of which isconnectedto a lever 82, as'best represented in Figure- 4;. Thecylindersare arranged in two adjacent the low gear'wheel is and-looking'towardthe left in Figure 1, it will be evident that the levers 82 are securedto the ends of shafts 84 which are mounted in the sides v85 of thev:gea-r box 28. The center portions of these shafts 84 V a are arcuatelyupset as at 88, toclear' the .drive shaft 40 and in the constructionillustratedalso to clear the gear wheel 32, and are provided with cammembers 90 adapted to f rictionally engage the annular flange platepr'tio'n'92 of the clutch In this connection, it sho uld be assembly 94.noted that the clutch vmechanisms will include dry clutch plates ,96which are rigidly secured, I as 'bythe bolts 98, tothe'drive shaft 82and coacting friction plates I00 are secured to plates 102 which may beformed integrally withth'e portions '82., the major portions of theclutch mechanism being recessed into the part of the gear box '8B, aswell illustrated inFigure 3. Frornthe foregoing, itw'ill' beevidenthowthe actuation of the levers 82 will cause the cams '50 to force theirictioh plates 100 against the plate 96', to engage the drive Shaft" I?With the driven shaft l4 fthroughthe medium of thegears concerned, ,asior'exar nple; the'gea'rs 32 andlfi. The essential j elements of theseclutch mechanisms will also in- "clude clutch release springs jlM whichmay be compressed between the inner "surface of the plates 9.2and theend iriction plate 96. I I A suitable selector valve for use in thisinvention is represented in Figure 5, and includes a cylindrical casingH36 having a removable cap Hl8. It will be noted that the inlett lcommunicatcs'with threebranc'hes I H) leading to the bore of the valve,and .tlu'ee registering outlets, named according to their connection'inFigure 5, are selectively; connected by the transverse channel Q H2 inthe valve plungerl M. The plunger H4 -is pro'vided with sealing rings H6andtwo channels I 18 extend from one side of the plunger to the centerthereof and" bent at right angles, as at 420;150 communicatewith'bleedports P22 which communicatewith the by-pass- 'l23,"i n'order to relievethe pressure on the opposite side' of the piston 80 when pressure isapplied to the base portion of the pistons'in engaging'the correspondingclutch, these bleed ports being effective also in-allowing thereverse how of fluidinto the ;--lines when-the clutch'isactuated by thesprings 104. '1 i The detailed construction: of the governor, .gen'erallylrepresented 'at I24,- is immaterial in this application, butwill ordinarily includefly: weights 1:126, toggle-links r28 connected toa fixed collar 30 and a sliding'collar I32, and-,-a spring i34.

It is to be understood that the governor is provided with 'asbevel edgear l3tfv which arranged gto be'in constant engagement'vdthabeveledgear irii fifirieidly secured to thedriven shaft [4 and theslidingtcollar B2 is engaged, in any suitable manner, with the end 4.2of the plunger, I M. "Variations in the-speed of rotation of the driven1 shaft-.14 will, therefore;- cause ithe' adjustments ra'of'thfiselector valve toconnect-the inlet 64selectively the low speed outlet[44, the inter- ;m'cdiate speedroutlet M6 orithe'shigh speedout- 4 letI48, these outlets being connected corresponding cylinders 14, I6 and18.

By-pass valves 150 are provided in each of the outlet lines, and theseValves may have a common control I52 which will ordinarily be connectedto the clutch pedal lever of the automotive vehicle 'whereon thisinventionis installed, to allow the instantaneous declutching of thedriving gears, whereby these valves are adjusted to communicate the saidoutlets With the reservoir 61 through the tube 54. In order to allow thewith the hydraulic fluid to escape from the cylinder on th'ewside of thepiston opposite to that vwhereon 7 pressure :is applied when the clutchisv engaged another Joy-pass valve, generally indicated by the numeral|-B,-is connected between a line I58 communicating the reservoir 60 withthe pump 38 and the four lines I60 connectingthe opposite side of thisby-pass valve Hill with the cylinders 'l2-'|8. The operation of thisby-pass :valve I56 is of a simple character since it serves merely-toopen or close connection between the .tubes 160 and the tube E58.;Whenthe plunger ,162 is in the position shown in Figure 1, none of theclutches may be engaged, but when the.

- plunger is moved as to the right in Figure 1; the

understood from a consideration of the foregoing of" the hub portion, ofthe description of the mechanical details thereof, taken in connectionwith the aboverecitation of the objects sought to be achieved by thisinvention but, it may be added that hydraulic fluid is taken from thereservoir by theenginedriven pump .38 which forces this fluid into theaccumulator 46, From the accumulator the fluid passes through theone-way valve '58, which will ordinarily be controlledby a foot pedal,and/or the driving in a forward directiom the three way 1 valve isplaced in starting position, that is, with the valve opened, toward theselector valve 10,

and the governor i24 will become operative in determining what gearratio will be used, the change from low to high gear, and from high'tolow gear when the load is increased being completely controlled bytheaction of this governor.

Declutching is made possible at any time, as fully I described above,and in other respects an automotive vehicle equipped with this inventionmay be operated in normal fashion.

Though there has been shown a particular embodiment of this invention,this application is not limited to this particular embodiment, but it isdesired to include in the scope of the invention, the construction;combination and arrangement.

of parts and portions substantially as set forth in theappended claims.

What Iclaim is: s

l -A hydraulic gearshift for variable speed gearing including a sourceof pressurized fluid connected to a selector valve, clutches operativelyassociated with gearing and having the selective engagement thereofcontrolled by said selector valvaand a governor controlling saidselector valve, said source being connected to a reservoir for saidfluid, said gearing including reverse gears, and a three-Way valveoperable to direct said pressurized fluid selectively to said reservoir,to the one of said clutches associated with said reverse gears, and tosaid selector valve.

2. A hydraulic gear shift for variable speed gearing including a sourceof pressurized fluid connected to a selector valve, clutches operativelyassociated with gearing and having the selective engagement thereofcontrolled by said se lector valve, and a governor controlling saidselector valve, said source being connected to a reservoir for saidfluid, said gearin including reverse gears, and a three-way valveoperable to direct said pressurized fluid selectively to said reservoir,to the one of said clutches associated with said reverse gears, and tosaid selector valve, and by-pass valves to by-pass said fluid aroundactuating means for said clutches.

3. A hydraulic gear shift for variable speed gearing including a sourceof pressurized fluid connected to a selector valve, clutches operativelyassociated with gearing and having the selective engagement thereofcontrolled by said selector valve, and a governor controlling saidselector valve and operatively connected with said gearing, said sourcebeing connected to a reservoir for said fluid, said gearing includingreverse gears, and a three-Way valve operable to direct said pressurizedfluid selectively to said reservoir providing a neutral drive positionof the gear shift and to the one of said clutches associated with saidreverse gears and to said selector valve for forward drive positions ofthe gear shift, and icy-pass valves to by-pass said fluid aroundactuating means for said clutches providing a second neutral driveposition of the gear shift.

JERRY C. CHAMBERLAIN.

REFERENCES CETED The following references are of record in the of thispatent:

UNITED STATES PATENTS Number Name Date 1,199,640 Vincent Sept. 26, 19161,731,076 Maurer Oct. 8, 1929 2,103,546 Livermore Dec. 28, 19372,283,133 Allen et al May 12, 1942 2,352,212 Lang et a1 June 27, 1944

